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Accuracy improvement capability of advanced projectile based on course correction fuze concept.

Elsaadany A, Wen-jun Y - ScientificWorldJournal (2014)

Bottom Line: The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved.The drag ring brake is found to be highly capable for range correction.On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate.

View Article: PubMed Central - PubMed

Affiliation: Nanjing University of Science and Technology, Nanjing 210094, China.

ABSTRACT
Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake) and the second is devoted to drift correction (canard based-correction fuze). The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.

Show MeSH
Atmospheric parameters versus altitude.
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Related In: Results  -  Collection


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fig3: Atmospheric parameters versus altitude.

Mentions: Variations in meteorological conditions have an effect on the projectile traveling through the atmosphere and hence affect its trajectory. The artillery projectile typically has peak altitudes of about 20 kilometers which is within the troposphere and is thus subjected to air density and drag. With increasing altitude, air properties such as density, temperature, pressure, and air viscosity change. Therefore, this changing is taken into consideration during the trajectory calculation to get an accurate prediction. For this purpose, a standard atmosphere model is developed based on the International Standard Atmosphere (ISA) [15]. Expressions for air density, ρ, and speed of sound, a, as a function of altitude, Z, can be derived and are given by(21)ρ=ρ0(TT0)((g/RL)−1)exp⁡(g(Ztrop−Z)RT),a=γRT,where T is the air temperature and is given by(22)T=T0−LZ,where ρ0 and T0 are the air density and air temperature at the sea level, respectively. g, R, L, Ztrop, and γ are gravity acceleration, real gas constant for air, temperature lapse rate, tropopause altitude, and adiabatic gas constant, respectively. Figure 3 depicts the variation of the air density, sound speed, air temperature, and air pressure as a function of altitude.


Accuracy improvement capability of advanced projectile based on course correction fuze concept.

Elsaadany A, Wen-jun Y - ScientificWorldJournal (2014)

Atmospheric parameters versus altitude.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4109594&req=5

fig3: Atmospheric parameters versus altitude.
Mentions: Variations in meteorological conditions have an effect on the projectile traveling through the atmosphere and hence affect its trajectory. The artillery projectile typically has peak altitudes of about 20 kilometers which is within the troposphere and is thus subjected to air density and drag. With increasing altitude, air properties such as density, temperature, pressure, and air viscosity change. Therefore, this changing is taken into consideration during the trajectory calculation to get an accurate prediction. For this purpose, a standard atmosphere model is developed based on the International Standard Atmosphere (ISA) [15]. Expressions for air density, ρ, and speed of sound, a, as a function of altitude, Z, can be derived and are given by(21)ρ=ρ0(TT0)((g/RL)−1)exp⁡(g(Ztrop−Z)RT),a=γRT,where T is the air temperature and is given by(22)T=T0−LZ,where ρ0 and T0 are the air density and air temperature at the sea level, respectively. g, R, L, Ztrop, and γ are gravity acceleration, real gas constant for air, temperature lapse rate, tropopause altitude, and adiabatic gas constant, respectively. Figure 3 depicts the variation of the air density, sound speed, air temperature, and air pressure as a function of altitude.

Bottom Line: The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved.The drag ring brake is found to be highly capable for range correction.On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate.

View Article: PubMed Central - PubMed

Affiliation: Nanjing University of Science and Technology, Nanjing 210094, China.

ABSTRACT
Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake) and the second is devoted to drift correction (canard based-correction fuze). The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.

Show MeSH